Posture is almost certainly associated with some pain problems, but much more weakly than most people believe. Postural habits with clear consequences and easy fixes are almost unheard of. Much of so-called poor posture is defined as just postural stress and being stuck with bad ergonomics not really a postural problem at all. Many people seem to be unusually vulnerable to poor postures and postural stress, but these people also may not have a posture problem, but a pain problem. A lot of more elements of poor posture are probably outcome of long-term biological adaptation that is either very hard or impossible to alter. About the only clear benefit to tinkering with posture is it can affect mood, emotion and probably pain degree of.
Trying to change posture is probably not worthwhile for most people, this.
However, if you want to test it and see, your best bet is probably increased activity, especially tasks that require coordination, and especially everything else you enjoy an activity that inspires, rather than a single that requires discipline. Ergonomic tuning may also be particularly helpful, especially with specific challenges. Technical and advanced methods taught by posture gurus are generally more or less wildly speculative and completely untested scientifically..